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https://github.com/doctormin/Hangzhou-Metro-Data-Visualizer
🚊 GUI implemented with Qt Creator
https://github.com/doctormin/Hangzhou-Metro-Data-Visualizer
Last synced: about 1 month ago
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🚊 GUI implemented with Qt Creator
- Host: GitHub
- URL: https://github.com/doctormin/Hangzhou-Metro-Data-Visualizer
- Owner: doctormin
- Archived: true
- Created: 2019-12-13T15:10:01.000Z (almost 5 years ago)
- Default Branch: master
- Last Pushed: 2020-04-02T03:24:34.000Z (over 4 years ago)
- Last Synced: 2024-08-01T19:46:26.612Z (4 months ago)
- Language: C++
- Homepage:
- Size: 1.45 MB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
- awesome-cs - @MinoZhao, 2019 Fall
README
# 🚉 Hangzhou Metro Data Visualization
***Environment: Windows 10***---
***Inplemented with Qt Creator***
## Introduction
----
**"Metro Insider"*** handles files with **SQLite in-memory database** with high efficiency, the following modules are implemented:
-> Loading Files with a Selector and Filter
-> SQLite Runner
-> Plotting & Analyzing
-> Route Planning
## Functions & Implementations Details
----
### Module 1 *-> Loading Files with a Selector and Filters*
#### Select Files and Set Filters
"choose a folder" button is expected to be pushed to start the whole process. It will open a dialogue to let users to **select the "dataset" folder**. It is implemented with `QFileDialog::getExistingDirectory()`.
Then a tree widget is created to let users choose files and filters implemented with `QTreeWidegetsItem`.
##### -> Files Tree
**The files tree can synchronize the child node with the parent node all the time**, with `Qt::Checked; Qt::PartlyChecked; Qt:Unchecked;` which means that
- parent `Partlychecked` $\Leftrightarrow$ some children `Checked`
- parent `Checked` $\Leftrightarrow$ all children `Checked `
- parent `Unchecked` $\Leftrightarrow$ all children `Unchecked`
- *It's implemented recursively.*
And names of all the chosen files is maintained in `QStringList chosen_files_names` timely **before**
the "load chosen files" bottom being pushed. (So the program won't have any problems when users change the checked items during the loading process.)
##### -> Filters Tree
It is designed for choosing the fields to be loaded into the **SQLite** database. But "time" & "stationID" & "status" can **not** be unchecked since our mandatory task requires a plot on "Inflow & Outflow of a station".
#### Loading Selected Files
Only selected fields of selected files will be loaded into the datatbase. The database would create a table whose columns are those fields. And this module has the following characteristics:
##### **-> High efficiency**
Loading the dataset of one day takes averagely 50s in my surface-Laptop (2017, 13.5'), it's relatively fast due to the insertion of data to SQLite can't be done by multicore.
##### **-> Multithreading**
With `` , the loading process is being done in another thread so the ui-thread will never be frozen.
##### **-> Status Bar**
The status bar is well designed to respond quickly to any situation
If users change filters or files selections after a loading, the status bar will suggest a renew.
##### **-> Robustness**
- Loading process is based on a file list maintained **before** "pressing the load button", so even if users change the file selection box or filters during the load, they won't have a problem.
- Reloading is well supported since the database will drop and create a new table newly designed for the chosen column and ensure there will not be a leak of memory.
- Before the loading process have been done, all the buttons and combo boxes relied to chosen files and filters will be disabled to avoid possible errors.
---
### Module 2 *-> SQLite Runner*
*SQLite Runner* is designed for any explore of raw data by users. It is implemented by `QTextEdit` `QSqlQueryModel` `QTableView` , it has following characteristics:
##### **-> Fast Speed**
- The database is in-memory and has a carefully designed **composite index**. So almost all the `SELECT` operation can be done in 0.x seconds.
- `QTableView` with `QSqlQuerymodel`makes it possible for **dynamic loading**, which means that the ui will not show all the results from e.g. `SELECT * FROM TABLE` at once so the ui will not freeze at any time. When users scrolls the table view, new query results will constantly be loaded
##### **-> Syntax Error & Running Error Information**
This function is implemented by
`ui->statusbar->showMessage(model->lastError().databaseText(), 100000);`
It will show any error message in the status bar.
---
### Module3 -> Plotting & Analyzing
